Doctor’s Note: Life in Plastic, It’s Not Fantastic — Microplastic and Nanoplastic Toxicity

We live in a world of plastic. You can wake up in bed covered with polyester sheets, turn off your plastic alarm clock, put on Lycra underwear and polyester clothes, take the plastic wrap off your breakfast bar, and slip on your “vegan leather” – plastic – sneakers. Then you climb into your car, sit your butt on a plastic seat, and zoom off on synthetic rubber… plastic tires.

So when you hear that researchers recently detected nanoplastics in carotid artery plaques, microplastics in human lungs, livers, gallstones, testicles, even placentas and breastmilk, you may find yourself asking questions. Are we being poisoned by the plastics in our environment? Is it true that microplastics are “this generation’s lead pollution”, as some have speculated? What are microplastics, anyway?

Microplastics (MP) refer to plastic particles smaller than 5 millimeters (the size of a pencil eraser) but larger than 1 micron (the size of a bacteria). Those smaller than 1 micron are called nanoplastics (NP). Some microplastics are intentionally manufactured at a small size, but most of them are created by wear and tear breaking pieces off a larger plastic material.

These tiny fragments are maddeningly difficult to detect, let alone count. There is no standardized technique for measuring the concentration of microplastics/nanoplastics in a sample of water, blood, or tissue. Testing with another technique can greatly increase how much plastic is measured, making it difficult to compare results between studies.

This difficulty of measurement has made it very tough to show just how much harm, if any, microplastic exposures have caused. Studies have shown that higher microplastic levels are associated with heart attacks and strokes, decreased sperm count, and earlier onset of gallstones, but we can’t prove that the microplastics actually caused the illnesses. It’s likely that people with unhealthy lifestyles and/or environments have higher exposure to microplastics. So, are the microplastics merely a marker for poor health, or did they actually cause the illness? We still don’t know for sure.

Some people might argue that if we can’t prove that plastics are directly harmful, we shouldn’t do anything to decrease their use. After all, synthetic plastics have improved people’s lives in many ways. Plastics are waterproof, non-conductive, lightweight, and easy to seal and sterilize. They’ve revolutionized healthcare with medical devices like syringes and catheters. Plastic wraps have greatly improved food safety and shipping, decreasing food waste. Plastic insulation is an indispensable part of electrical wiring, switches, and fittings. And plastic interiors have made vehicles lighter and more fuel-efficient.

But there’s a strong argument to be made in favor of caution. Plastics in the environment can last up to 500 years. If they’re causing any toxicity today, they’ll keep on doing it for generations to come. And human industry is churning out plastic at a far higher rate today than ever before. So, we owe it to future generations to limit plastic waste as much as we can.

As an individual, there are ways you can limit the plastics you put in your body and the environment. You can use cloth bags and cloth napkins, avoid bottled water and plastic drinking straws, and wear clothes made out of natural fabrics instead of synthetics. You can eat as many fresh foods as possible, limiting the amount of plastic packaging in contact with your food. You can seek out natural materials like wood, steel, glass, ceramics, and leather in lieu of plastic tools and containers. You can avoid exposing plastics to heat, as even a “microwave safe” food container will shed more microplastic when heated. You can put your used plastics into recycling bins, though that might not be as helpful as we once thought (we’ll get to that in a bit).

Decreasing plastic pollution on a global scale is much more difficult, and will require large-scale international efforts. Plastic debris removal has proven effective, removing hundreds of tons of plastic from the sea. The United Nations Environment Programme (UNEP) is actively negotiating a global treaty on plastic pollution that aims to limit the amount of plastic waste worldwide. And many U.S. states have worked toward reducing or eliminating single-use plastics.

Why can’t we just recycle it? Plastic recycling has been controversial for years. A 2022 Greenpeace report showed that plastic placed in recycling bins was mostly burned, buried, or dumped. Other organizations like End Plastic Waste are working on “plastic circularity” — better techniques and technologies for real-world recycling. That said, as an individual it’s hard to tell if the plastics you put in the recycle bin will actually be recycled. It’s always better to avoid or re-use plastics rather than throw them away.

So, are microplastics responsible for heart disease and infertility and poor gut health? We don’t know yet. Plastics do not have strong toxicity data like lead, tobacco, carbon monoxide, or asbestos. And none of us can avoid plastics entirely. They are far too common, and in many cases the benefits outweigh the harms. But we can work on eliminating plastic waste, and on limiting our exposures in food and drink.